Flight simulators such as the Stewart platform (Stewart, D. 1965, "A Platform with Six Degrees of Freedom," Proc. Institute of Mechanical Engr., London, England, Vol. 180, pp. 371-386) have been used and studied as parallel manipulators. Kohli et al. (Kohli, D., Lee, S. H., Tsai, K. Y., and Sandor, G. N., 1988, "Manipulator Configurations Based on Rotary-Linear (R-L) Actuators and Their Direct and Inverse Kinematics," Trans. ASME, J. of Mech., Transmis., and Auto. in Design, Vol. 110, pp. 397-404) studied six-degree-of-freedom (six-DOF) parallel manipulators which are driven by base-mounted Rotary-Linear actuators. Hudgens and Tesar (Hudgens, J. C., and Tesar, D., 1988, "A Fully-Parallel Six Degree-of-Freedom Micromanipulator: Kinematic Analysis and Dynamic Model," Trends and Developments in Mechanisms, Machines, and Robotics--Proc. of the 20th Biennial Mechanisms Conference, ASME, New York, DE--Vol. 15-3, pp. 29-37) introduced a new six-DOF parallel micromanipulator suitable for serial-parallel systems. Pierrot et al. (Pierrot, F., Fournier, A., and Dauchez, P., 1991, "Towards a Fully-Parallel 6 DOF Robot for High-Speed Applications," Proc. of the 1991 IEEE International Conference on Robotics and Automation, pp. 1288-1293) introduced a high-speed six-DOF parallel manipulator.